epigenetics

Studying zebrafish embryos, researchers at Washington University School of Medicine in St. Louis have shown that the epigenome plays a significant part in guiding development in the first 24 hours after fertilization. The research may deepen understanding of congenital defects and miscarriage.

In the Aug. 28 issue of the journal Nature, a multi-institution research network called modENCODE (the Model Organism ENCylopedia Of DNA Elements) published three major papers that map and compare the genomes and epigenomes of humans and two model
organisms, the fly, D. melanogaster, and the worm, C. elegans, in unprecedented detail. The fly and worm could serve as model organisms for screening drugs and micronutrients that might alter the epigenome, which is implicated in many diseases.

A Washington University in St. Louis team is participating in the modENCODE project, a massive ongoing effort to map all the elements in model organisms that affect whether genes are silenced or expressed. The work supports the more complex ENCODE project, which is tasked to map the same elements in the human genome. While the genome is the same in every cell, each cell type expresses a different set of genes. In people, moreover, roughly 95 percent of the genome is silenced. Together the projects will “put flesh on the bones” of the Human Genome Project, says team leader Sarah C.R. Elgin.

Olga Pontes is Going FISHin’.Biologists at Washington University in St. Louis have made an important breakthrough in understanding a pathway plant cells take to silence unwanted or extra genes using short bits of RNA. Basically, they have made it possible to see where, and how, the events in the pathway unfold within the cell, and seeing is believing, as the old saying goes. Craig Pikaard, Ph.D., Washington University professor of biology in Arts & Sciences and his collaborators have described the roles that eight proteins in Arabidopsis plants play in a pathway that brings about DNA methylation, an epigenetic function that involves a chemical modification of cytosine, one of the four chemical subunits of DNA. More…

Richards has observed the inheritance of epigenetic factors in plants.Eric Richards, Ph.D., professor of biology at Washington University in St. Louis, writing in the May issue of Nature Reviews Genetics, analyzes recent and past research in epigenetics and the history of evolution and proposes that epigenetics should be considered a form of soft inheritance, citing examples in both the plant and mammalian kingdoms.